////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2012-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if ! defined (octave_oct_refcount_h)
#define octave_oct_refcount_h 1

#include "octave-config.h"

#include <atomic>

namespace octave
{
  // Encapsulates a reference counter.

  template <typename T>
  class refcount
  {
  public:

    typedef T count_type;

    refcount (count_type initial_count)
      : m_count (initial_count)
    { }

    refcount (const refcount&) = delete;

    refcount& operator = (const refcount&) = delete;

    ~refcount (void) = default;

    // Increment/Decrement.  int is postfix.
    count_type operator++ (void)
    {
      return ++m_count;
    }

    count_type operator++ (int)
    {
      return m_count++;
    }

    count_type operator-- (void)
    {
      return --m_count;
    }

    count_type operator-- (int)
    {
      return m_count--;
    }

    count_type value (void) const
    {
      return m_count.load ();
    }

    operator count_type (void) const
    {
      return value ();
    }

  private:

    std::atomic<T> m_count;
  };
}

#endif
